Sardonic is an excellent word for some of Austen's writing. Perhaps I didn't think of it here because Austen can be even more biting in her letters and some of her other fiction, esp. Sense and Sensibility. But I agree: your view works, too, and I'll keep it in mind for my next piece about Austen (about whom I've written many times and will always be glad to revisit). Thanks so much for your well-informed perspective.